Automatic starting mechanism



Aug. 22, 1933. M, P, WHITNEY AUTOMATIC STARTING MECHANISM Filed Feb. 28, 1951 INVENTOR mum P WILL-fine BY A TTORNEY l lowing description taken in connection with the engine.

Patented Aug. 22, 1933 PATENT OFFICE AUTOMATIC STARTING MECHANISM Maurice P. Whitney, Elmira, N. Y., assignor to Eclipse Machine Company, Elmira, N. Y., a. Corporation of New York Application February 28, 1931 Serial No. 519,022

6 Claims. (01. 290-3 This invention relates to automatic starting mechanism for internal combustion engines and more particularly an overload releasing device for an automatic starting switch having a manually controlled detent for'retaining the parts in'releasing position.

In the operation of starter gearing for internal combustion engines, it may sometimes happen when the starting pinion is moved into engagement with the engine gear, that a tooth of the pinion engages end to end and wedges tightly against a tooth of the engine gear, preventing proper engagement and cranking of the If this should occur in an automatic starter installation, the starting circuit would remain closed and cause an undesirable heating of the motor and connected elements and an unnecessary drain on the starting battery. Certain types of overload releasing devices for opening theautomatic starting switch under these conditions have been provided, among which are arrangements for utilizing the heating effect of certain elements of the starting circuit to efiect the releasing function. Unless such devices are equipped with some form of detent for holding the parts in released position, however, the cooling of the parts will cause reengagement of the starting switch, which reengagement might be inopportune in case, for instance, the operator were then engaged in effecting the .re lease of the starter gears and had neglected to open the manual control switch.

It is an. object of the present invention to provide an overload release for automatic enginestarting mechanism including. a novel device for retaining the parts in released position.

Another object of the invention is to provide such a structure in which the retaining device is adapted to be manually operated to place the parts again in position for automatic operation.

A further object is to provide such a device which is reliablein operation, and simple and economical to manufacture and install.

Further objects and advantages will be apparent to those skilled in this. art from the folaccompanying drawing in which:

Fig. 1 is a semi diagrammatic illustration of a preferred form of the present invention, the automatic starting switch being shown in elevation and partly in section; and

Fig. 2 is a 'sectiontaken substantially on the line 2-2 of Fig. 1.

In Fig. 1' of the drawing there is illustrated va starting motor circuit including a battery 10,

one terminal of which is grounded as indicated at ll, the other terminal of which is connected by means of a lead 12 to an automatic starting switch including the stationary elements 13 and 14 and the movable bridging element 16. Switch element 14 is connected to a single turn coil 17 which is connected by a lead 18 to the starting motor SM, the latter being grounded at 19 and being adapted when energized to crank an internal combustion engine, not illustrated. The v single turn coil 1'7 is provided with an adjustable magnetic core 20 surrounded by a spacing sleeve 30.

The bridging switch element 16 is mounted on a movable magnetic plunger 21, suitably insulated tl'ierefrom, which plunger is normally maintained in its upper position as illustrated by means suchp as a spring 15 but which may be drawn down? to close the starting switch by solenoid 22. Saidsolenoid is included in a con'- trol circuit comprising battery 10, lead 12, manual switch 23, lead 24, lead 25, contacts 26, 2'7, spring strip '29 and ground connection 28. Spring strip 29 carries the movable contact 27 and normally holds the same against the stas0 tionary contact 26 whereby closure of the manual switch 23 by the operator will cause the energizaticn of solenoid 22 to close the starting switch and energize the starting motor. Manual switch 23 is preferably arranged to control the ignition circuit of the engine as indicated, so that closure of said switch will simultaneously close the ignition circuit and operate the automatic starting mechanism.

Means are providedfor automatically opening the control circuit when the engine starts, for holding said circuit open as long as the engine is self-operative and for delaying the closing thereof until a predetermined time after the engine has comesubstantially to rest.

As illustrated,these means include a wedgeshaped weight member 31mounted on the end of the spring strip 29 in the path of movement of a roller 32. Said roller is mounted on the end of a lever 33, pivoted at 34, and having a pin 35 at an intermediate point thereof projecting laterally between a pair of flanges 36 and'3'7 on a movable magnetic relay plunger 38. A voltage coil 39 and agenerator coil 41 are arrangedto surround the lower part of the 'relay plunger 38 and when energized attract it downwardly. The voltage coil, 39 is connected at one end by a lead 42 to the'stationary switch member 14 and is grounded at its other end as indicated at 43. Generator coil 41 is connected at one end by a lead 44 to the generator G and is also grounded at its other end at 43. Plunger 38 is normally retained in its upper position against the spacing sleeve 30 by means such as a spring 46 whereby the lever 33 is maintained, as illustrated, out of contact with the weight member 31 so that contacts 26 and 2'7 are normally closed.

In the operation of the device so far described, closure of the ignition switch 23 completes the control circuit from the battery 10 through lead 12, switch 23, lead 24, coil 22, lead 25, contacts 26 and 27, spring strip 29 and ground connection 28. The consequent energization of coil 22 causes switch plunger 21 to move the starting switch member 16 into contact with switch members 13 an 14, thus completing the starting circuit from battery 10 through lead 12, starting switch 13, 16, 14, single turn coil 17, lead 18, starting motor SM and ground connection 19 whereby the starting motor is caused to crank the engine. During this time the voltage coil 39 is energized by reason of its connection to the starting switch member 14, but the heavy current traversing the single turn coil 17 magnetizes the adjustable core 20 therein sufficiently to hold the relay plunger 38 in its upper position.

When the engine starts, the load on the starting motor is relieved, and the consequent reduction of the current through the single turn coil 17 together with the increase of voltage drop through the voltage coil 39 enables the latter to overcome the client of the single turn coil 1'7 and draw the plunger 38 downward. This causes the lever 33 to carry the roller 32 into engagement with the weight member 31 and bend the spring strip 29 backward sufiiciently to disengage contact 27, from contact 26.

The consequent opening of the control circuit causes the release of the switch plunger 21 .whereby the spring 15 operates to open the against its pole piece 40 until the starting motor has come substantially to rest. Before the voltage coil .39 becomes, entirely deenergized, the generator G which is driven from the engine builds up suflicient voltage to energize the generator coil 41 and retail the relay plunger 38 in its lower position, thus holding the contact 27 open as long as the engine is self-operative.

If the engine should stall for any reason, the coil 41 becomes deenergized and the spring 46 raises the relay plunger 38 releasing the weight member 31 which vibrates for a predetermined length of time due to its pendulous mounting on the spring strip 29 thus. giving the engine. time to come completely to rest. When the vibration ceases, and the contact 27 comes to rest against the contact 26, the starting operation is repeated.

If, during the starting operation, the starting motor is stalled for any reason, such as by a jamming of the starter gearing, so that it is unable to crank'the engine, a very heavy flow of current traverses... the starting circuit since it is not opposed by a counter electro-motive force built up. in the starting motor. This causes the elements of the starting circuit to become heated, this heating effect being particularly noticeable in the elements of the starting switch and in thearmature of the starting m0- tor. In order to protect these elements from overheating and in order to prevent unnecessary drains on the startingbattery, means are provided to cause the starting switch to be opened in response to a predetermined rise in temperature of the elements of the starting circuit.

As herein. illustrated, this is accomplished through the instrumentality of a heat responsive element in the form of a bi-metallic strip 47 mounted at one end on an element of the starting switch such as the stationary contact element 14 and thermally connected thereto. The free end of the -bi-metallic strip is adapted to bend to the right in Fig. 1 when the temperature thereof is raised, and is connectedto a strip 48 of insulating material in any suitable way as by entering a notch 49 in the end thereof. The insulating strip 48 may be guided for longitudinal movement by suitable means such as stationary pins 50 (Fig. 2) and is suitably articulated with a lever 51 at an intermediatepoint thereof. Lever 51 is mounted at one end on a fixed pivot 52. and terminates at its other end 53 adjacent-the spring strip 29.

It will be seen that the connection so formed between-the heat responsive element 47 and the spring strip 29 is such that movement of the free end of the heat responsive element to the right in Fig. 1 is transmitted to the spring strip 29 to move the contact 2'7 away from contact 26, thus breaking the control circuit.

According to the present invention, manually controlled means are provided for retaining the spring strip 29 in its open position until released by the operator. As illustrated, this means takes the form of a latch member 54 slidably mounted adjacent the insulating strip .48 and adapted to enter a notch 56 therein.

Latch 54 is provided with a flanged head 57 which engages in a notch 58 in a bell crank lever 59 mounted to swing on a fixed pivot 61. The bell crank lever 591s controlled by a link 62 terminating in a button 63 which is adapted to be depressed by the operator. Means such as a spring 64 is provided for urgingv the link 62 7 in a direction to cause the latch 54 to engage in the notch 56 whenever registry thereof occurs. In operation, if the starting circuit is closed in the manner above described and the-starting motor should be stalled for any reason, the switch element 14 will become heated by the heavy flow of current therethrough and will transmit this heat to the bi-metallic element 4'7 causing the free end of the same to move to the right in Fig. 1. Insulating strip 48 is thus moved to the right and lever 51 is caused to engage the spring strip 29 and bend the same backward. Contact 27 is thus moved away from the fixed contact 26, breaking the controlcircuit and releasing the starting switch plunger 21. The movement, of the insulating strip 48 causes the notch 56 to register with the latch. 54 whereupon the latter enters said notch and locks the strip against return movement.

The starting circuit. is thus held open-until the operator, after releasing the jammed condition or the starting gear, depresses the button 63 thereby withdrawing the latch 541mm the notch 56, allowing the contact 27 to engage contact 26. If the manual switch 23 is then closed,

the startingoperation willflthereupon' be. re-" peated. v

' It will be understoodthat the dimensions of the heat responsive element 47, its attachment to the switch element 14 and its connection to the spring strip 29 are such that a suitable interval of time is required for the heat of the switch element to be conducted to the heat responsive element and cause its operation. Un-

desired or premature operation thereof is thus avoided.

Although but one form of the invention has been shown and described in detail, it will be understood that other embodiments are possible and that various changes might be made in the proportions and arrangements of the parts without departing from the spirit of the invention as defined in the claims appended hereto.

What is claimed is:

1. An automatic starting system for internal combustion engines including a starting motor circuit, a control circuit therefor including a pair of contacts, means for operating said contacts to cause the starting circuit to be opened when the engine becomes self-operative, means cooperating with said first named means for operating said contacts to cause the starting circuit to be opened in response to an overload thereon and manually controlled means for preventing the return of said contacts to normal position.

2. Automatic starting mechanism for internal combustion engines including a starting motor circuit, a control circuit therefor including a pair of normally closed contacts, manual means for closing said control circuit to cause the starting circuit to be closed, automatic means for opening said contacts to cause the starting circuit to be opened when the engine is selfoperative, means cooperating with said automatic means for opening said contacts in response to an overload on the starting circuit, means cooperating with said last named means for holding said contacts open, and manual means for releasing said holding means.

3. Automat c starting mechanism for internal combustion engines comprising a starting motor circuit including an automatic starting switch, a control circuit for said switch including a pair of contacts, a heat-responsive element thermally connected to an element of said starting circuit, connections between said heat responsive element and said contacts whereby a predetermined rise in temperature of said heatresponsive element will operate said contacts to allow the switch to open, and a manually controlled detent for preventing the return of said contacts to normal position.

4. Automatic starting mechanism for internal combustion engines comprising a starting motor circuit including a starting motor switch, a control circuit for said switch including a pair of normally closed contacts, a heat-responsive element thermally connected to an element of said starting circuit, connections between said heat-responsive element and said contacts whereby a predetermined rise in temperature of said heat responsive element will open said contacts to allow the switch to open, and a manually controlled detent operating on said connections to prevent the closing of said contacts.

5. Automatic starting mechanism for internal combustion engines comprising a starting motor circuit including an automatic starting switch, a control circuit for said switch including a pair of normally closed contacts, a heat responsive element mounted on a member of said switch and thermally connected thereto, a mechanical connection between said heat-responsive element and said contacts whereby a predetermined rise in temperature of said switch member will open said contacts, a latch for holding said contacts open and manual means for tripping said latch.

6. Automatic starting mechanism for internal combustion engines comprising a starting motor circuit including an automatic starting switch, a control circuit for said switch including a pair of normally closed contacts, a heat-responsive element in the form of a bi-metallic strip mounted at one end on a member of said starting switch and thermally connected thereto, a connection between the free end of said strip and said contacts whereby a predetermined rise in temperaturepf said switch member will open said contacts, a latch cooperating with said connection for holding said contacts open, and a manual tripping device for releasing said 120 latch to allow said contacts to close.

MAURICE P. WHITNEY. 

